Sprung! The 300kW Holden Commodore SS

UPDATED: Holden is believed to be investigating how images of its HSV-rattling Commodore were snapped deep inside its top-secret proving ground.

The leaked images show Holden's last-ever Aussie-made Commodore is shaping up for a 300 kilowatt-plus V8-fuelled swansong.

The images, published on industry website GoAuto overnight, show what looks like a Chevrolet-nosed version of the highly anticipated VF Series II, which as well as more aggressive, hardline looks, boasts a bigger, more powerful V8 engine.

The brand refused to speculate on the images, saying only that they do appear to have been taken from inside its top-secret Lang Lang proving grounds in a location far away from prying lenses.

Mirroring what is already happening with its US export model, the Chevrolet SS, the Commodore’s last significant makeover before the tap is turned off Australian production in late 2017 is expected to shelve the 270kW 6.0-litre and instead shoehorn the US market’s 6.2-litre V8 – opening the door to tyre-smoking HSV-rivalling performance for Commodore money.

With VF Series II due in showroom later this year, Wheels understands bigger power and sharper styling are just part of a raft of changes to ensure Commodore remains relevant until 2017.

The V8 models, which account for about one in three Holden Commodore sales, will once again cop the brunt of the changes, which could include a sharper and stiffer suspension tune and substantial brake upgrades. A new bi-modal exhaust system and a recalibrated ESC that adopts Holden’s competition mode, currently exclusive to SS-V Redline models, are also possible.

Bigger and tougher-looking alloy wheels – wider at the rear just like the current SS-V – will complete the makeover, which could also see high-performance variants adopt bonnet vents, if this testing mule’s heavily camouflaged nose is any indication.

Wheels believes that similar to the last mid-life refresh of the Commodore range, V6 variants will relieve lighter upgrades with little to no change to the existing 185kW 3.0-litre and 210kW 3.6-litre engine line up.

Another sign of things to come is the loss of the Commodore’s bee-sting antenna, which is replaced with a more stumpy version. It hints that upgrades to the Commodore’s in-car multimedia system will be enhanced further, with digital radio and even in-car wireless internet hub likely.

Despite the leak, Holden refused to shed new light on future Commodore models, except to say it is committed to ensuring the Commodore name remains relevant “until 2017 and for many years after”.

It also wouldn’t be drawn on whether the expected upgrades would see Commodore prices increase to reflect the improved hardware.

HSV, meanwhile, has also remained tight-lipped over how the threat of a 300kW-plus Commodore with cut-price, HSV-killing performance would impact its business.